Antihypertensive Medications: Classes, Actions, and Nursing Safety

Antihypertensive medications are among the most commonly tested drug categories on nursing exams. This guide reviews the major classes, their mechanisms, side effects, hold parameters, and core nursing safety rules you need to manage patients with hypertension safely.

Major Antihypertensive Classes

• ACE inhibitors (e.g., lisinopril) — lower BP and provide kidney protection.
• ARBs (e.g., losartan) — lower BP without causing cough.
• Beta blockers (e.g., metoprolol) — lower heart rate and BP.
• Calcium channel blockers (CCBs) (e.g., amlodipine) — lower BP and/or HR.
• Diuretics (e.g., furosemide) — decrease fluid volume.
• Vasodilators (e.g., hydralazine) — decrease afterload.

First-Line Hypertension Medications

1. Thiazide diuretics
2. ACE inhibitors
3. ARBs
4. Calcium channel blockers

Mechanisms of Action

• ACE inhibitors: Block formation of angiotensin II.
• ARBs: Block angiotensin II receptors.
• Beta blockers: Decrease heart rate.
• CCBs: Cause vasodilation or slow HR.
• Diuretics: Remove excess fluid.

Common Side Effects

• ACE inhibitors: Dry cough, hyperkalemia.
• ARBs: Hyperkalemia.
• Beta blockers: Bradycardia, fatigue.
• CCBs: Constipation, peripheral edema.
• Diuretics: Electrolyte imbalances.

Life-Threatening Risks

• Severe hypotension
• Bradycardia
• Electrolyte disturbances
• Angioedema (with ACE inhibitors and ARBs)

Hold Parameters

• SBP < 90–100 mmHg → hold medication.
• HR < 60 bpm → hold medication.
• Critical electrolyte imbalance → hold and notify provider.

Nursing Safety Rules

• Check blood pressure before administration.
• Monitor electrolytes and renal labs.
• Teach patients to make slow position changes to prevent orthostatic hypotension.
• Promote medication adherence.
• Do not stop beta blockers abruptly (risk of rebound hypertension, tachycardia, and ischemia).

Common Exam Traps

• Confusing antihypertensive drug classes.
• Giving medications despite hypotension.
• Ignoring potassium levels.
• Abrupt discontinuation of beta blockers.
• Forgetting pregnancy contraindications (ACE inhibitors and ARBs).

Key Takeaways

• ACE inhibitors and ARBs lower BP and provide kidney protection but can cause hyperkalemia and angioedema.
• Beta blockers lower HR — always check pulse before giving and never stop abruptly.
• CCBs affect BP and/or HR and commonly cause edema and constipation.
• Diuretics reduce fluid volume but require close monitoring of electrolytes.
• Always assess BP and HR before administration; hold for SBP < 90–100 or HR < 60.
• First-line therapy: thiazides, ACE inhibitors, ARBs, and CCBs.